Cross-site scripting in Avast AVG Antivirus

Published: 2019-11-05 | Updated: 2019-11-05
Severity Low
Patch available YES
Number of vulnerabilities 1
CVE ID CVE-2019-18654
CWE ID CWE-79
Exploitation vector Network
Public exploit Public exploit code for vulnerability #1 is available.
Vulnerable software AVG Antivirus Internet Security Edition Subscribe
Vendor Avast Software s.r.o.

Security Advisory

This security advisory describes one low risk vulnerability.

1) Cross-site scripting

Severity: Low

CVSSv3: 5.5 [CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N/E:P/RL:O/RC:C] [PCI]

CVE-ID: CVE-2019-18654

CWE-ID: CWE-79 - Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

Description

The vulnerability allows a remote attacker to perform cross-site scripting (XSS) attacks.

The vulnerability exists in the Network Notification Popup due to insufficient sanitization of user-supplied data passed via an SSID Name. A remote attacker can trick the victim to follow a specially crafted link and execute arbitrary HTML and script code in user's browser in context of vulnerable website.

Successful exploitation of this vulnerability may allow a remote attacker to steal potentially sensitive information, change appearance of the web page, perform phishing and drive-by-download attacks.

Mitigation

Install update from vendor's website.

Vulnerable software versions

AVG Antivirus Internet Security Edition: 19.3.3084

CPE External links

http://firstsight.me/2019/10/5000-usd-xss-issue-at-avast-desktop-antivirus-for-windows-yes-desktop/
https://medium.com/@YoKoKho/5-000-usd-xss-issue-at-avast-desktop-antivirus-for-windows-yes-desktop-1e99375f0968

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability. However, proof of concept for this vulnerability is available.